Typically, a computer system contains a processor, a bus, and other peripheral devices. The processor is responsible for executing instructions using the data in the computer system. The bus is used by the processor and the peripheral devices for transferring information between one another. The information on the bus usually includes data, address and control signals. The peripheral devices comprise storage devices, input/output (I/O) devices, etc.
The most heat intensive device in a computer system is the processor, also referred to commonly as the central processing unit (CPU). All processors generate heat. As processors have become faster and more complex, the amount of heat generated as a result of their use has increased. However, the heat generated by a processor is exponentially proportional to the processor clock speed. Therefore, the heat generated has increased by an amount greater than their gain in speed.
As the temperature of the devices in a computer system rises, the temperature within the computer system also rises. A rise in the internal temperature of a computer system may cause problems. For instance, computer components typically have certain temperature operating ranges outside of which they may fail (e.g., they do not run correctly). Also, if the computer system includes a shell, such as one constructed of plastic, the shell may heat to a temperature capable of burning a person who comes in contact with it.
Typical computer systems use cooling systems to compensate for the heat generated by their components. These cooling systems normally include fans in desktop and larger computer systems. Portable computers are common in the market today. These portable computers, referred to as laptop and notebook computers, do not usually have the space or energy capacity available for fan-based cooling systems. Therefore, it is desirable to provide a means for cooling the internal temperature of a portable computer.
Recently, computer systems have began to include power management capabilities. These power management capabilities include the ability to turn off one or more components in a computer system, such as a processor, in order to reduce the power consumption in the system. These power management mechanisms are particularly useful in conserving power, and therefore, extend battery life, in battery-powered portable computers. An example of such a system having power management capabilities is described in U.S. Pat. No. 5,239,652, where the power to a processor is removed for short periods of time during inactivity, while the remainder of the computer system remains powered. The processor is periodically powered at regular intervals to accommodate any processor tasks and requests that might have occurred while the processor was "powered down."
The present invention provides a thermal management mechanism for a computer system. The present invention is particularly useful in a portable system to maintain the internal temperature at a level within the operating ranges of the components. The present invention also manages the internal temperature to ensure that the shell or container for the computer system does not reach a temperature capable of burning human skin.